Case 580K Diesel Backhoe Gets Fuel but Won’t Start

[MikePhua]

The Case 580K and Its Mechanical Simplicity
The Case 580K backhoe loader, produced throughout the 1980s and early 1990s, was part of Case’s highly successful 580 series—a line that helped define the compact loader-backhoe market. With a naturally aspirated or turbocharged diesel engine, mechanical injection system, and straightforward hydraulics, the 580K was built for durability and ease of service. Case Corporation, founded in 1842, had already sold hundreds of thousands of backhoes by the time the 580K was introduced, and many units remain in active use today.
Despite its reputation for reliability, the 580K is not immune to fuel system issues—especially when contaminated fuel enters the tank. A common scenario involves the machine receiving fuel but refusing to start, even after filter changes and tank flushing.
Dirty Fuel and the Chain Reaction of Blockages
Introducing dirty fuel into a diesel system can trigger a cascade of problems. Even after draining the tank and replacing filters, residual contaminants may remain in the lines, pump inlet, or internal screens. In the 580K, fuel flows from the tank through a primary filter, into the injection pump, and then to the injectors. If flow is confirmed before the pump but absent after, the blockage is likely internal.
Critical components to inspect:

• Inline filter (often overlooked during service)
  
• Banjo bolts at fuel line connections (can trap debris in their internal screens)
  
• Inlet screen beneath the injection pump’s fuel fitting
  
• Fuel shutoff solenoid (electrically controlled valve that allows or blocks fuel delivery)
  

One technician in Illinois recalled a 580K that refused to start after a fuel tank cleaning. The culprit was a clogged banjo bolt screen—cleared with compressed air and a dab of diesel-compatible lubricant.
Fuel Shutoff Solenoid and Electrical Verification
The fuel shutoff solenoid is mounted on the injection pump and controls fuel flow based on ignition key position. If the solenoid fails or loses voltage, it will remain closed, preventing fuel from reaching the injectors.
Steps to verify solenoid function:

• Turn key to “on” and listen for a click at the pump
  
• Use a multimeter to confirm voltage at the solenoid terminal (typically 12V)
  
• Check ground continuity from solenoid body to chassis
  
• If no voltage is present, trace wiring back to ignition switch and fuse panel
  

In one case, a 580K in New York had a failed solenoid wire hidden beneath the battery tray—damaged by corrosion and vibration. Replacing the wire restored fuel flow instantly.
Injection Pump Inlet Screen and O-Ring Maintenance
The Stanadyne or Roosa Master injection pump used on many 580K models includes a fine mesh screen beneath the inlet fitting. This screen can become clogged with rust flakes, algae, or filter debris—especially after fuel system service.
To clean:

• Remove the inlet fitting using a ¾-inch wrench
  
• Extract the screen and blow it out with low-pressure air
  
• Inspect the O-ring for cracks or flattening
  
• Lubricate the O-ring with clean diesel and reinstall carefully
  

Neglecting this screen can lead to pump starvation, hard starting, or complete failure. A pump rebuilder in South Carolina emphasized that 30% of pump failures he sees begin with clogged inlet screens.
Priming the Fuel System After Service
After draining the tank or replacing filters, air may remain trapped in the fuel lines. The 580K’s mechanical injection system requires manual priming to restore pressure.
Priming steps:

• Open bleeder screws on the filter housing and pump body
  
• Use the hand primer (if equipped) or crank the engine with injectors cracked
  
• Watch for steady fuel flow at each bleeder point
  
• Tighten fittings once bubbles disappear
  

Some operators install an electric lift pump to aid priming, especially on machines used seasonally or in cold climates.
Cold Start Challenges and Seasonal Adjustments
In colder regions, diesel engines may struggle to start due to thickened fuel and reduced battery output. The 580K can be equipped with:

• Block heaters to warm coolant and reduce cranking load
  
• Glow plugs or intake heaters to aid combustion
  
• Synthetic diesel-rated oil (e.g., 5W-40) for better cold flow
  

Battery health is also critical. A Group 31 battery with at least 950 CCA is recommended for reliable cold starts.
Conclusion
A Case 580K that receives fuel but won’t start is often suffering from a hidden blockage, electrical fault, or air lock. By inspecting inline filters, banjo bolts, solenoids, and inlet screens, operators can restore fuel flow and get the machine running again. With its mechanical simplicity and rugged design, the 580K remains a favorite among owners who value hands-on diagnostics and field serviceability. Whether clearing snow, digging trenches, or grading driveways, this classic backhoe deserves clean fuel and a bit of mechanical attention to keep earning its keep.